Michael ate 1 slice of cake. Emily ate 3 slices. If Michael ate $\dfrac{1}{7}$ of the cake, what fraction of the cake was eaten?
If 1 slice represents $\dfrac{1}{7}$ of the cake, there must have been a total of 7 slices. $\text{fraction of cake eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${4}$ out of $7$ slices. They ate $\dfrac{4}{7}$ of the cake.